A. Field of Invention
The present invention relates to surgical cutting instruments, and particularly to cutting instruments for laparoscopic surgery, where the instrument is inserted and withdrawn through a very small tube, which is inserted through a very small laparotomy.
B. Problems in the Art
A wide range of cutting needs exist in surgery. Different instruments have been developed to attempt to meet these needs. Examples include scalpels, scissors, wire loop cutters and saws.
These type of cutters have generally satisfied the types of cutting procedures needed in most types of surgery. However, as medical procedures change and become more sophisticated, the types of cutters and methods for using them change.
Recently, a combination of technology and techniques have allowed some surgical procedures to be performed less traumatically and invasively with respect to the patient's body. In other words, instead of requiring a large incision, or combination of incisions to more less open up the patient to gain access to interior organs, vessels, or areas, some procedures can be accomplished through a combination of very small openings. Technology such as fiber optic lighting, laparoscops, and very small cameras are utilized to allow the surgeon to view internal areas of the body through a very small tube either directly or on a television screen. The small tube is usually referred to as a cannula or a trocar. The primary advantage to this type of surgery is a substantial decrease in the amount of time needed for the patient's recovery. Large incisions through substantial parts of the patient's body require weeks and months of recovery time. If the invasion into the body is made through small holes or openings, however, this can be reduced quite significantly.
A very practical problem regarding instrumentation is created, however. The size of the small opening into the patient limits the size of the instrument that can be moved to the location within the patient's body. It also affects the mechanics of how the instrument can be operated.
Still further, such procedures represent a drastic shift in the frame of reference of the surgeon. The surgeon must view a television screen instead of viewing directly the surgical location, the instruments tips and the surgeon's interaction with the instruments. This impacts on what type of instruments are best for these procedures.
Laparoscopic cholecystectomy is an example of this type of surgery. Small incisions of only 5 and 10 MM (millimeters) are made in the patient's abdomen. Gallbladder removal involves cutting the ducts leading to the gallbladder. A laparoscope combined with a small camera is inserted through a 10 MM trocar and the internal area of interest is then televised for the surgeon.
There is risk in cutting requirements, such as the ducts associated with the gallbladder. It is imperative that the surgeon isolates and positively identifies the duct. The duct must be held in the isolated position during cutting, and this is difficult to accomplish with scissors.
Other types of laparoscopic surgery, where instruments are inserted through a small incision, or even simply surgery which requires reliable cutting of small portions, may experience these same problems. Less invasive types of surgery therefore has created the need for a better type of surgical cutting instrument.
It is therefore a principal object of the present invention to provide a surgical cutting means which improves over or solves the deficiencies and problems in the art.
Another object of the present invention is to provide a surgical cutting means which provides a reliable cutting action for specific types of cutting requirements of small items or portions of items.
Another object of the present invention is to provide a surgical cutting means which is easy to operate, and is capable of holding the element to be cut during cutting.
Another object of the present invention is to provide a surgical cutting means which shrouds the sharp cutting blade to prevent damage to the blade during insertion and removal through a small trocar.
Another object of the present invention is to provide a safe means of inserting the instrument into the patient thus preventing spurious cutting.
Another object of the present invention is to provide a shroud after cutting so that the sharp blade will not cut anything beyond the cutting stroke.
A still further object of the present invention is to provide a surgical cutting means which isolates the object to be cut before the cutting stroke is executed.
Another object of the present invention is to provide a surgical cutting means which can be inserted deep into the body cavity, operated, and withdrawn, without damage to the patient.
Still further object of the present invention is to provide a surgical cutting means which is easy to maintain and repair.
Another object of the present invention is to provide a surgical cutting means which is efficient, economical, and durable.
These and other objects features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.